Some Considerations respecting the Parietal Bone. 



323 



111 Galesaurus planiceps the aiitero- posterior diameter of the 

 frontal is two thirds that of the parietals. A prefrontal is figured 

 by Zittel. 



Placodiis gigas (Muschelkalk) has the aiitero-posterior diameters of 

 the frontal and parietal bones equal (Zittel). 



Fig. 11. 



Hatteria punctata. 



Parietal 



A large Nilelizard has 2,0 cm 



„ „ Alligator ,, 3,1 ,, 



„ „ Turtle „ 4,0 ,. 



„ ,, Hatteria ,, 4,2 „ 



r :, Boa „ 3,3 „ 



Ant. Par. lat. 



A large Struthio has 1,2 x 2,5 cm 

 „ „ Owl „ 0,6x1,0 „ 



Gallus „ 0,8 





Fig. 12. 





Boa. 



Frontal 



3,0 



cm 



5,0 



,, 



1,5 



,. 



3,8 



51 



1,7 



7: 





Frontal 



3,0 



cm 



2,5 



xl „ 



2,8 



n 



21* 



